1. Field
The disclosed embodiments relate to a device and a method for protecting against ice accretion for aircraft engines.
2. Brief Description of Related Developments
Due to operating constraints and in particular due to the waiting times before take-off, aircraft, particularly civil aircraft, are subject to exposure time in considerable icing conditions with their engines idling.
Although the engines are running, these conditions entail the risk of accumulating large amounts of ice on the static (or not) upstream parts of the engines and in particular on the blades of the low-pressure compressor, commonly known as an air blower, or fan, which rotates at a low speed when the engine is idling, or on the fixed downstream parts of the air blower or the inner wall of the front part of the engine nacelle, in particular in the area surrounding the air blower, or fan.
In order to reduce ice accretion in the engines, ground methods exist for ensuring regular de-icing of the engines.
These methods involve periodically increasing the speed of the engine so as to centrifuge the ice accumulated on the rotating parts and increase the temperature of the engine airflow downstream from the air blower, in order to remove any ice which may have accumulated on the fixed parts of the engine.
These methods require the flight crew to monitor the time spent in icing conditions during the taxiing stage after landing as well as during taxiing prior to takeoff and the outside temperature.
Furthermore, the methods systematically implemented when the supposed icing conditions are reached do not take into account the real amount of ice accumulated and lead to increased fuel consumption and unnecessary pollution of airports.
Ice detection systems exist for detecting icing conditions during the flight. These systems are based on a probe equipped with an ice-sensitive element, which transmits information when the aircraft passes through an icing cloud.
These devices, which have the main aim of warning the crew but can also be used to automatically engage the icing protection systems of the plane, comprise a probe requiring an airflow to provide reliable information.
Such a probe can furthermore be installed in the air intake of the engine and be subjected to the airflow sucked in by the engine, which also enables it to provide information when the plane is performing ground operations.
In this case, the probe is also used to activate an alarm indicating the presence of ice but it does not make it possible to determine the actual amount of ice accumulated.